First off, this isn't a third gen. But I need to fix this thing so I can sell it in order to be able to afford a paint job for my camaro. Anyways. I have a 74 Ford Gran Torino Elite (like a TBird) w/ a 400 in it. I had low oil pressure, around 9 lbs, then a lifter collapsed on me. I did the lifter, put in a high volume oil pump, and it was still only around 9 psi. I know no oil is getting to the upper part of the motor. Anyways, the oil pressure dropped down to nothing on me and the freeway, and that's where it's staying. It started running loud, too. It was staying around 20 psi while I was driving, then suddenly went down. The new oil pump only has like 50 miles on it. I've been told the bearings are probably worn, and I can't see any other possible problem. In general, how would I go about doing rod and main bearings? I've also been told that if I'm going to bother doing bearings, I may as well do a full rebuild, but I would rather not do that. I just wanna get some pressure so it runs right and I can sell the car, cuz I gotta get my maro painted

 

easiest and best way to do it would be to pull the engine, take it apart, have it cleaned, replace bearings, rings ,oil pump, and gaskets and reinstall.

 

k, thanks

 

Have you checked the oil pressure with another gauge besides the one in the dash?

 

i've got a second gauge in the car, and it should be accurate. the car suddenly got louder wen i saw the gauge drop. there's only an idiot light in the dash. now i'm not too sure about bearings, would they just go instantly like that on me? i figure they're wore, there's 149k on the motor. But i was driving on the freeway, it was stayin around 20 lbs., then just went down to nothing. i may try the oil pump again first, and see what happens. What else can cause oil pressure to drop on an old block?

 

Z2885,

'74 400, "S" engine. Check the "twist-off" oil pump drive shaft. It's a ¼" hexagonal shaft that twists itself into a pretzel whenever the oil pump picks of an object.

And other than the causes listed above, possible reasons for complete loss of oil pressure could be:

• Loose oil pump puckup screen flange joint (it's bolted on);
• Oil pump relief valve stuck open;
• Incorrect oil filter (failed bypass valve and plugged media;
• Inadequate oil level in the sump;

I'd pull the distributor and look at the shaft first.

 

And remember, this is supposed to be a ThirdGen ONLY tech site...

 

k, thanks for the info, and i'll stop posting non thirdgen topics. and where exactly is the oil pump relief valve? what do I look for in pulling the distributor?